Submersible electric motor



March 12, 1940. I I G MY R ET AL 2,193,463

SUBMERSIBLE ELECTRIC MOTOR Original Filed Feb. 27, 1932 (0000a) 000000) o 0oooa (D0000) mooomo 040000030 INVENTORS omqs G. M ers ATTORNEY Patented Mar. 12, 1940 UNITED STATES 2,193,463 sunmnasmrn ELECTRIC Moron Thomas G. Myers, Los Angeles, Calif., and Mason, Chicago, Ill., assignors to U. S. Electrical Motors, Inc., a corporation of California Original application February 27, 1932, Serial No.

8 Claims.

This invention relates to electric motors, and especially to submersible motors for operating deep well pumping units.

This application is a division of an application filed in the names of Thomas G. Myers and Frank Mason, for Submersible pump motor, February 2'7, 1932, Serial No. 595,590.

-It is common to pump liquid from a deep well, such as an oil well or a water well, by submerging a pumping unit, comprising a pump and an electric' motor, in the well. To prevent ingress of the liquid being pumped tothe motor casing with resultant injury to the motor windings or other parts, the casing must be carefully sealed. Since the unit may be operated at a depth of'several hundred feet or more, the pressure of the well fluid is high, and the casing is accordingly subjected to a large stress, with a probability that the fluid will be forced into the motor parts.

It is a principal object of this invention to obviate the necessity of any packing or sealing of the motor casing and yet to prevent the entry of well liquid into the motor parts.

This object is accomplished'by supporting the motor in the top of a structure, the bottom only of which is open. When such a structure is submerged, air is trapped therein by the surrounding liquid, and is "compressed as the level of the liquid within the structure rises. This serves to keep the liquid from reaching the motor. By making the structure sufiiciently long, the volume of the trapped air will be great enough to permit the lowering of the structure to a considerable depth without the liquid reaching the motor.

Alternatively, means may be provided to fur,-

nish gas to the.motor space in the structure for the purpose of creating a pressure within it to balance the pressure of the well fluid. This may be to supplement the volume of trapped air,

thereby reducing the required length of the structure, or it may be merely to make up for air that is lost from any cause.

Another object of this invention to provide a novel form of electric motor incorporating the open ended casing and having a greatly simplified construction.

This invention possesses many other advan-' tages, and has other objects which may be made more easily apparent from a consideration of one embodiment of the-invention, For this pur-- Divided and this application 23, 1937, Serial No; 160,480

August the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referring to the drawing, the single figure is a diagrammatic view of a submerged pumping unit, in operative position in a well, the motor being shown in longitudinal section.

In the drawing, there is shown by way of example, a well casing I from which a liquid 2 usually water, or a mixture of water and other substances is to be pumped. Suspended in this liquid'is a pumping unit 3 which includes a pump 4 and an electric motor 5. The pump may be of the centrifugal type and is secured to the lower end of the discharge pipe 6. A perforated cylindrical member I forming an intake is secured to the lower end of the pump, and to this member in turn is secured a frame 8 which serves to support the motor. The .pump shaft 9 extends downwardly a short distance below the pump and a radial bearing I0 is provided in frame 8 to receive it. Attached to the lower end of the shaft,

as by screw threads, is the structure H which i is open at its lower end as indicated by [2. .This structure forms the motor casing and has the motor 5 positioned in its upper end. As it is closed at its upper end, air will be trapped and compressed in it when it is lowered into the well liquid; Obviously, as the structure is lowered ing this is by decomposing the well l'iquid within the structure to form gas. Thus, electrodes 13 and I4 may be supported on frame 8 in the open end I! of the structure, the passage of electricity between-them serving to break down the liquid and form gas ina manner well understood.

The structure II which serves as a casing for the motorcomprises a tubular member, or bell, which is closed at its upper end by a wall I 5 I having a central hub 55in which the shaft 9 is secured. The depending wall or skirt ll of the bell may be flared or tapered outwardly toward its lower end, and the bottom is entirely open at -l2, asprecious] ,mentioned.- Since the casing II is rigidly attached to the load driving shaft 9, it Obviously must rotate. 'Io impart rotation to it, the secondary member l8 or rotor is outside the primary or stator l9 which is fixed and carries the primary winding 20. The stator I9 is supported on a central shaft or column 2 I, whichis rigidly secured to a plate 22 spanning the bottom of frame 8. Column 2| has a bore 23 or hollow part through which conductors 24 lead to the winding 20. A conduit 25 is sealed into plate 22 and serves to carry these conductors to the top of the well. Roller bearings 26 and 21 are secured to shaft 2| above and below the motor and serve to rotatably support casing ll coaxially with respect to the shaft.

Since the casing l I is entirely closed at the top, air will be trapped and compressed therein, serving to check the rise of well liquid inside the casing due to the pressure of the liquid outside the casing. Due to the large bottom opening l2, the pressures inside and outside equalize at once, and any change in the external pressure as when the pumping unit is being raised or. lowered in the well, produces immediately a corresponding change in the internal pressure. Thus casing H is never subjected to any pressure differential. The flare of skirt I1 is effective to prevent any undue rise of the liquid in the casing due to centrifugal force, as the casing rotates.

What is claimed is: 1. In a submersible structure, a driven shaft and a rotatable housing fastened to said shaft.

' said housing being sealed at its upper end and unsealed at its lower end, an electric motor inthe housing and near its top, the rotating part of the motor being fastened to the housing to cause it to rotate. g

2. In a submersible structure, a driven shaft and a rotatable housing fastened to said shaft, said housing being sealed at its upper end and unsealed at its lower end, an electric motor in the housing and near its top, the rotating part of the motor being fastened to the housing to cause it to rotate, and a support for the stationary part of the motor, said support extending into the housing from the .lower end thereof.

3. The combination as set forth in claim 1, in which the housing is outwardly flared toward the bottom.

4. In a submersible structure, a driven shaft and a rotatable housing fastened to said shaft, said housing being sealed at its upper end and unsealed at its lower end, an electric motor in the. housing and near its top, the rotating part of the motor being fastened to the housing to cause it to rotate, a support for the stationary part of the rotatable housing enclosing said motor and supporting said rotor, said housing being sealed at its upper end and open at its lower end, bearing means on the shaft to rotatably support the housing, a driven shaft connected to the housing and adapted to be connected to a load, and electric current carrying means leading outwardly from the stator winding through the bore in the stationary shaft.

6,.In a submersible structure, a support,'a shaft secured to said support and extending upwardly therefrom a housing rotatably supported on said shaft, said housing being sealed at its upper end andopen at its lower end, an electric motor in the housing near its top, the rotating part of the motor being fastened to the housing to cause it to rotate, the stationary part of the motor being mounted on said shaft, and a load driving shaft fastened to said housing. 1

7. In a submersible structure, an electric motor having a stationary member and a rotating'member, means forming a rotatable housing for said motor and adapted to be rotated by said rotating member, there being an opening in said housing only at the bottom, said housing having a lower edge extending for a considerable distance below the motor and a load driving shaft connected tothe housing.

8. In a submersible structure, an electric motor having a stationary member and a rotating member, means forming a rotatable housing for the motor and adapted to be rotated by said rotating member, said housing being open only at the bottom, a supporting member extending upwardly within the housing, bearing means on said member to support said housing, the walls 

